The invention relates to package handling method for transferring collations of flexible packages from a first location to a second location and to a corresponding package handling apparatus.
In package handling systems such as an installation for collating a number of packages and loading them into a carton, it is often convenient to lift the packages from above, for example, to transfer them from a conveyor to a carton or from one conveyor to another conveyor. A well established procedure for lifting packages from above is to employ suction heads against which packages are drawn. One known way of handling a collation of packages is to provide a matrix of several suction heads, for example twenty such heads arranged in a 4.times.5 matrix, to lower the matrix over a collation of packages and then to apply suction to the heads to support the collation on the matrix of heads. Conventional heads of this kind require a relatively high vacuum. They are normally supplied from continuously running suction pumps. In order to provide sufficient suction for most of the heads when one or perhaps two other heads are not closed off by a package, the pump requires sufficient capacity to generate an appropriate level of suction even with unrestricted flow through a small number of heads. An inevitable result is a requirement for a large capacity suction pump which is expensive to install and operate, runs noisily and generates unrequired heat. In a factory environment with several such installations side by side, the noise and heat provide undesirable working conditions. An arrangement of this kind can only be used if the individual packages have sufficient flat or nearly flat areas on their upper sides.
It is already known, for example from Wahl et Al U.S. Pat. No. 2,716,497 to employ a single large loading head comprising an enclosure having an opening, a permeable barrier extending across the opening and suction within the enclosure to hold a collation of packages against the barrier and thereby enable the complete collation to be transferred from one location to another. Arrangements of this kind are known either for rectangular shaped packages which form closely packed collations or with a requirement for very large flow rates requiring noisy and power consuming pumps or fans to compensate for leakage around packages which do not nest closely together. For the latter, see for example UK Published Patent Application No. 2113178A.
An object of the present invention is to provide an improved package handling process and an associated apparatus in which disadvantages of prior proposals can be reduced or overcome.